Why Is My Garbage Disposal Humming But Not Working?
A humming garbage disposal that won't spin is almost always jammed. Here's how to unjam it yourself in a few minutes — and when to call a pro.
By Tyler
If your garbage disposal hums when you turn it on but nothing happens, the motor is running but the grinding plate is stuck — meaning it's jammed. This is the most common disposal problem and usually something you can fix yourself in 5 minutes without any special tools. Here's exactly what to do.
Step 1: Turn It Off Immediately
A disposal that's humming but not spinning is straining its motor. If you leave it running, it will trip the internal thermal overload switch (which protects the motor) and possibly overheat. Flip the switch off right away.
Step 2: Use the Allen Wrench Socket at the Bottom
Look under your sink at the bottom center of the disposal unit. You'll see a small hex socket (usually 1/4" or 5/16"). This is specifically designed to let you manually turn the grinding plate and free whatever's jamming it.
Most disposals come with a small Allen wrench for this purpose — it may be taped to the unit or in the bag of hardware from installation. If you don't have it, a standard Allen wrench from any hardware store works.
Insert it into the socket and work it back and forth. You'll feel resistance at first — that's normal. Keep working it until the plate spins freely in a full circle. This usually takes 30–60 seconds.
Step 3: Clear the Jam from Above
Once the plate is moving freely, shine a flashlight into the disposal from the top and look for what caused the jam. Common culprits: a bottle cap, a piece of flatware, a cherry pit, a small bone, a twist tie, or a chunk of food that got compacted.
Never reach in with your hand while the disposal is connected to power. Use tongs, needle-nose pliers, or a wooden spoon to remove whatever you find. Don't use your fingers — even a "off" disposal can catch skin on the sharp impellers.
Step 4: Press the Reset Button
After freeing the jam, press the small red reset button on the bottom of the unit. This resets the thermal overload switch. You'll feel it click in.
Step 5: Test It
Turn on cold water, then flip the disposal switch. It should spin up immediately and sound normal. Run water for 30 seconds after it clears to flush everything through.
What If It's Still Just Humming?
If you've freed the jam, reset the button, but it still only hums without spinning, the motor's start capacitor or the motor itself may have burned out from running while jammed. At that point, repair vs. replace is worth considering — a new disposal runs $150–$300 installed, while a motor repair on an older unit often isn't worth it.
What If It Makes No Sound At All?
A completely silent disposal (no hum, no sound) is a different problem — it's not getting power. Check:
- The reset button — press it firmly. If it pops back out immediately, the thermal overload is still tripped. Wait 15 minutes for the motor to cool, then try again.
- The outlet under the sink — many disposals are plugged into a switched outlet. Check that the outlet works with another device.
- The wall switch wiring — occasionally a wire connection at the switch comes loose.
- Your circuit breaker — a disposal draws significant current and can trip the breaker.
What Not to Put Down a Garbage Disposal
Most jams are preventable. The disposal's job is to handle small, soft food waste — not to be a general food processor.
Avoid putting in: bones, fruit pits, fibrous vegetables (celery, artichoke leaves), potato peels in large amounts, pasta or rice (they expand with water and form a paste), coffee grounds in large amounts, and grease or cooking oil.
Run cold water before, during, and after using the disposal. Hot water melts grease, which then re-solidifies further down the drain and causes clogs.
When to Call a Technician
You can handle most jams yourself with the steps above. Call a pro if:
- The disposal is leaking from the bottom (usually a failed internal seal — often means it's time for a new one)
- The unit is leaking where it connects to the sink drain
- You've freed the jam and reset it but it still won't spin
- You're replacing the disposal entirely and want it done right the first time
I handle garbage disposal repairs and replacements throughout Greater Boston and the North Shore. Most jobs are quick — often completed in under an hour.
Frequently Asked Questions
How do I know if my garbage disposal is jammed vs. burned out? If it hums, the motor is running — it's jammed. If it's silent with no sound at all, it's either not getting power or the motor has failed. The fix for each is different.
Can I use my sink if the disposal is jammed? Yes — the disposal is on a separate branch of the drain. You can still use the sink, but be careful not to let food scraps go down while the disposal isn't working.
How long do garbage disposals last? Most disposals last 10–15 years with reasonable use. InSinkErator and Moen tend to hold up well. If yours is over 12 years old and the motor has failed, replacement makes more sense than repair.
Why does my disposal smell bad even when it's working? Food residue builds up under the rubber splash guard and along the inner walls. To clean it: turn off power, use a scrub brush to clean under the rubber flaps at the top, and grind a few ice cubes with some coarse salt followed by lemon or orange peels.
My disposal is leaking from the bottom — can it be repaired? A bottom leak usually means the internal seal around the motor housing has failed. On most units, this isn't worth repairing — a new disposal is more cost-effective than replacing internal seals.
Disposal jammed and the Allen wrench trick didn't work? Or is it leaking and you need a new one installed? Book a visit and I'll get it sorted out fast.